Train control



W. K. HOWE TRAIN CONTROL May 2 1956.1.

Fi led Jan, 31, 1925 SPEED CON TROLL ED V Patented May 20, 1930 UNITEDSTATES PATENT OFFICE WINTH ROP K. HOWE, OEROGHESTER, NEW YORK, ASSIGNORTO GENERAL RAILWAY 4 SIGNAL COMPANY, OF ROCHESTER, NEW YORK TRAINCONTROL Application filed January 31, 1925. Serial No. 6,067.

This invention relates to automatic train control systems for railways,and more particularly to a combination of means which requires theengineer to take appropriate action, which for convenience may be calledacknowledgment, at or near each of a plurality of successive stopsignals in order to avoid a penalty such as an automatic applipation ofthe brakes which requires the train )to be brought substantially to astop.

More specifically, it is proposed in accordance with the presentinvention, to require the engineer to perform an acknowledging act atsuccessive points or intervals of distance during the travel of thetrain while running under a stop signal through a danger or occupiedblock or series of blocks. It is proposed to require the acknowledgingact for the first danger signal to be enforced a certain distance fromthe caution signal, and on those systems where the various blocks are ofthe same length it is proposed to require the engineer to acknowledgethe first danger signal at a point beyond a caution signal which willassure bringing the train to a stop from the speed limit imposed at suchpoint before it reaches the stop signal, and for systems in which theblocks are not the same in length the acknowledging point for the firstdanger signal is preferably selected so as to satisfytherequirementswhen approaching the signal at danger at the exit end of theshortest block of the system. Inthe form of the invention illustrated,acknowledgment of stop signals only is required, but obviously provisionfor theacknowledgment of caution signals in addition to theacknowledgment of stop signals may be added if desired.

Other objects, purposes and characteristic features of'this inventionwill in part be obvious from the drawings and in part appear as thedescription thereof progresses.

In describing the invention in detail, reference will be made to thesingle drawing which illustrates a train control system of thetwoposit-ion continuous inductive type in a diagrammatic andconventional manner.

= Although the present invention is applicable to various types of traincontrol systems, such as intermittent systems of various kinds andcontinuous inductive type systems of the three-position orthree-condition type, it has been shown applied to a simpleform oftwoposition continuous inductive type of train control system so as tosimplify the illustra tion and the description of the same.

Two/away apparatus In the particular embodiment of the inventionillustrated, the trackway has been shown asconsisting of rails 1 dividedby insulating joints 2 into blocks, of which the block I and theadjacent ends of two other blocks H and J have been illustrated. Sinceall of the various blocks are the same, at least in automatic asdistinguished from interlocked train control territory, like parts ofeach block are designated by like reference characters hav ingdistinctive exponents. At the entrance to each block is provided awayside signal of any of the well known types, and for conveniencethree-position semaphore signals Z, only have been illustrated, whichsignals have been shown conventionally without illustrating theiroperating mechanism or control circuits. Each of these signals assumesthe clear position if the block at the entrance to which such signal islocated and the next block in advance are unoccupied, assumes a cautionposition the next block in advance is occupied and assumes a dangerposition if the block at the entrance to which it is located isoccupied. At the entrance of the block I, the normal direction oftraflic being as indicated by the arrow, is located the usual trackrelay T which under'normal clear traffic conditions is energized by thetrack'battery 3 connected across the exit end of this block. Thisbattery is connected in series with the secondary winding of thetransformer 4 this transformer havingits primary winding connected tothe transmission line 5 through a circuit including the front contact6of the track relay T From the above description of the trackwayapparatus it readily appears that direct current is applied across theexit end of each ance with occupancy of the block, and that alternatingcurrent is superimposed upon this direct current of a block if the nextblock in advance thereof is unoccupied. Also, it appears that eventhough alternating current is applied across the exit end of a block,this current cannot reach a train entering such block if the block isalready occupied by another train, this because said another train willshunt this alternating current away from In other words, it

the train in question. readily appears. that if a train having suitablemeans for detecting the flow of alternating current flowing down onetrack rail and back through the other ahead of such train is movingalong the'track, such train cannot detectv alternating current if itenters an occupied block because this alternating current is shuntedaway by the train ahead, and that such train cannot detect alternatingcurrent when entering an unoccupied block when the block next inadvancethereof is 00- cupied, because no alternating current isimpressed across'the railsat the exit end of the block in question duetothe fact that the front contact of the track relay of the block aheadis in its retracted position; and there-. fore alternating current isonly detected on the train when the train in question is moving inclearterritory. 7

In the drawing isillustrated a train by the wheels and axles 10,directly in front of the first; axle of which are located influence'receiving elements each comprising a core 11 having a winding 12thereon. Thesewindings 12 are connected in series in such a manner thatvoltages induced therein, due to currents flowing down one rail ahead ofthe train,

through the axles'of the train and backthrough the other rail, arecumulative. The

wires leading from these windings 12 are connected to the input leads ofa suitable amp'lifying device A, which device preferably includessuitable sources of energy, tuning devices, filtering devices andamplifying tubes of the vacuum type'and which amplifying device has itsoutput leads connected to a main relay MR. 7

The apparatus thus far described includes the trackway apparatus and theinfluence receiving apparatus located on a car, andit Y immediatelymanifested by this relay MR regardless of the position of the train inthe block. r I

Oar-carried apparatus Generally speaking, the car-carried appa ratus isof the type in which suitableme'ch anism driven from the wheels of thevehicle is set into operation under predeterminedl traffic conditionsand is similar to that disclosed in a series of patents issued to P. J.Simmen as for example, Patent No. 1,150,308

dated August. 17, 1915, and also similarto' that disclosed in theapplication of W. K Howe, Serial No. 783,975' filed August 2 5, 1923; sothat a detailed illustration and description of the system is notnecessary. In

systems of the kind mentioned, a speed responsive device (notspecifically shown) is located on the train, which device at alltimesindicates the actual speed at which the train is moving, and thshaft for driving this speed responsive device is at times operativelyconnected to suitable cam shafts so as to drive these shafts inaccordance with the progress of the train along the trackway. V In orderto simplify the description of the present in-. vention' the specificmanner in which these cam shafts may bedriven by a shaftconnected to theaxles of the vehiclehas not been illustrated, butahigh cam startermagnet I-IGS which governs the clutching engage- V ment of the high tolow speed control shaft 16, shown by a dot and dashline, has been shown.This shaft 16 carries a distance camv 17 and a permissive speed cam 18.1y, there is provided a speed shaft 19, also illustrated by a dot anddash line, which shaft at all times assumesa position dependent on theactual speed of the vehicle; and this speed shaft controls the speedsector 20 which closes its contacts 69 at aspeed below two miles perhour, and the speed arm 21; If desired of course, parts 20 and 69 couldbe omitted so that an automatic'brake appli- Similar:

ids

cation would necessitate bringing the train to a full stop. The speedarm 21 and permissive speed cam 18 through fioatinglever 22 control thecam-governor contacts'23 through the medium of the sector 24. Thespeedsector 20, the cam-governor contacts 23,

and the distance cam 17 correspond in almost 7 every respect to thespeed sector 29, the camgovernor contacts 110. and the distance camshown in the application of Howe above referred to, so that a detaileddescription of this mechanism need not be given; here.

On. the train is provided another shaft, conventionally called theacknowledging shaft and illustrated by dot and .dash line 25. This shaftnormally assumes a biased position by reason of suitable biasing means(not shown) and'by means of the energization of the acknowledging camstarter magnet ACS. This shaft 25 is gradually rotated in accordancewith the progress of the train if the cam starter. magnet ACS isdeenergized for the same reason that I gle mechanism is moved "fromshaft 16 is rotated in accordance with the ing under a stop or dangersignal, and to" inflict a penalty if the engineerfails to do so whenrequired, and in order to force the engineer to make such repeatedacknowledgments the present invention con-templates res toration andre-initiationof the. acknowledging shaft 25 after a distance of travelofsaid shaftfrom its normalposition.

In order that the acknowledging shaft 25 may be restored to its biasedposition automatically by means controlled by itself 'the restoring cam30 is provided with switch mechanism of the-toggle type. This mecha-'nism, in the particular embodiment illustrated, consists of twoswitchmembers '32 and 33 pivoted at 34 and 35 and operatively connectedby the link36. These switch members 32 and 33 assume either of theirextreme positions, which are determined bythe engagement of rollers 37"and 38against the curved surface of the cam 30, by'th'e action of thetoggle spring 39 which spring tends to maintain this toggle mechanism inthe last position to which it was operated by the cam portion '70 on thecam 30. This toggle spring 39.is oneof the compressiontype and iscontained on the bifurcated guide rod 40 between the shoulder 41 and thewasher 42 on this rod, and the'bifurcated portion of this guiderodstraddles a stationary pin 43, so that the spring 39 is compressed for atime asthe tog one extreme position to the other. 7 i Sincethe presentinvention does not relate to any particular type of brake controlmechaanism, but relates to train control systems generally which mayinclude brake control mechanism of any desired type, anelectro pneumaticvalve EPV has been illustrated for this purpose. This device EPV uponde- 7 energization may vent the brake pipe directly or maycontrolsuitable pneumatically operated brake control mechanism of anydesired typge.

efore'the operation of the car-carried apparatus is taken up in detail,it iscon'sidered expedient to trace the normally closed circuits. Undernormal clear 'traflic conditions ofthe' car-carried apparatusillustrated the main relay MB is energized for reasons heretofore given.I With the relay MR energized relay MR, wire 82, winding of the'high cam370 2 starter magnet HOS, wire 83 back to-a common return wire Cconnected to the other terminal of said source of energy. I

I With the high cam starter magnet HCS energized the permissive speedshaft '16 assumes its normal biased position so that the sector 24 onlyopens thecontacts 23 when the speed of the trainis above a maximumofsay, inilesperhour. With this cam shaft '16 in its normalposition,'the distance cam 17'allows the contacts 46 to remain closed,thereby maintaining a closed energizing circuit for the acknowledgingcam starter magnet ACS which may be traced asfollows; beginning from theterminal'B, wire47, contacts 46, wire 48, winding of the cam startermagnet HCS, wire 49 to the common return wire C. I

With the acknowledging-cam starter magnet ACS energized theacknowledging cam shaft 25 assumes its normal position, in which it hasbeen illustrated, thereby maintaining a closed'energizing circuit forthebrake applying device EPV which may be traced as followsz-beginningat the terminal'B, wire 62, contacts 63 operated by the cam 28, wire 50,contacts 51, operated by the acknowledging-cam 29, wires device EPV,Wires 57 and 58 Windin of the device EPV, Wire 59 back g to commonreturn wire 0. It should be noted that the circuit.

52, 53 and 54, cam-governor contacts 23, wire 55, front contact 56 ofthe able from B, contact finger and front contact 26 of MR, wire 27,contacts 23, wire 55, "stick contact 56 of EPV, wires 57and5'8, EPV, andWire 59 to C. cuits will be aointed out in the o eration of the system.ith the device EP the brakes of the vehicle may be'controlled by theengineer, and the brakes may be. as sumed to be releasedat this time.

The functions of'these cir-' energized,

It maybe pointed out at this time that the car-carriedv apparatus isshown in its'normal clear t'ra'flic condition w1th the train moving ataspeed above, say, 2 miles per hour and less than 60' miles per hour, sothat the contacts controlled by the speed sector 20 are open and thepermissive speed or cam-governor contacts '23 are closed.

Operation MR train is moving in a clear block, but assumes As heretoforeexplained, the main relay assumes its energized. position if the danger.to caution in which case the relay MR remains unchanged.

'Let us assume that the tram is proceeding 7 along the trackway in aclear block and enters acaution block. Asthe train enters thecautionfblock the main relay MR assumes its deenergized ,positionthereby deenengizing the high cam starter magnet HCS which in turn Iinitiates the cam shaft 16,-so that thev permissive speed atwwhic'h thevehicle may travel is gradually reduced through the medium of a floatinglever 22 and the permissive speed train restricted to a suitable minimumof say lf) miles per hour at the run-out of this I cam 18, thispermissive speed cam 18 being preferably so shaped that the permissivespeed is restricted in accordance with a speed distance brakingcharacteristic for a par ticular train and so that the speed of the cam.When the high camshaft 16 has almost reached 7 its ultimate position,the

projecting portion of the cam 17 engages the roller 60 thereby causingthe contacts46 to open, and thereby deenergizing the acknowledging camstarter magnet'ACS and initiate ing the acknowledging cam shaft 25,WVith the acknowledging cam shaft operatively'connected to the wheels ofthe train V perform an acknowledging act in order to by reason ofdeenergization of :this cam starter magnet ACS, the signal cam 28, after7 a. shortdistance of movement 'of the train, closes contacts 61,thereby applying energy to the acknowledging signal lamp 62 so that theengineer if alert is informed that he must avoid a penaltyfwhich penaltyin the par automatic brake application requiring the train to be broughtsubstantially to a stop. Proceeding "on the assumption that the engineeris alert and seesthe indication signal given by the acknowledging signallamp .62- he" depresses the push buttonPB and in so doing causes thispush button to beheld down by the holding magnet 22, this holding magnet being strong enough to hold the push button PB down but beingunable to move this push button to its depressed position.

- With thepush button PB inits depressed I position a supplementalorauxiliary circuit for the device EPV is closed, which circuit is thesame as the one heretofore traced through 62, 63 except that it includescontact 65 of thepush button PB and Wires 66 and 68 instead of contacts51 and wire'52. 7' It should be noted that'depression of thejpushticular arrangement shown consists of an button PB extinguishes theacknowledging signal lamp 62;

As the train pr'o'ceeds ai little farther into the, caution block,-theacknowledging cam 29' is rotated to a position to allow the roller 67 toride into one, of the notches of'this cam,

depending on the direction of movement of' the train (pilot or tenderleading) thereby opening the contacts 51. It should be noted, that ifthe engineer hadnot depressed +he push button PB; the device EPV wouldhave been deenergized andan automatic'brake ap-, a

plication would have been imposed by reason .of opening ofthese contacts51,;but since the r i I push button PB hasbeen depressed and .is E

now. held in its depressed "position by the holding magnet 22, thedevice EPV is maintained energized through this auxiliary cir-T cuit solong as contacts 51 are open, As the train proceeds a little farther thecontacts51 are" again closed after: which the contacts 61 are againopened, thereby opening the auxe iliary circuit and breaking theenergizing circuit for the holding magnet 22, thus allow ing the pushbutton PB to returntoits normal position It maybe pointed out at "this Jtime that the distance moved by the train in a caution block before thecontacts 46 are opened, plus the distance moved by the train from thetime'the acknowledging cam starter magnet is deenergized by theopeningjof these contacts to the time when contacts 51 open, is suchthat if the engineerfails to acknowledge the first caution signal thetrain is sure to be broughtto a vstopby an automatic brake applicationbefore it reaches thefsigna'l at danger,- it being remembered that thetrain has been restrictednto its minimum speed, of say 15 miles perhour,- at

the time such acknowledgment is'required.

.If, an automatic brake application isim- V posed by the'opening of thestick circuit for the device EPV for anyofthe reasons'here- V tof'oregiven, this device EPV remains deenerg zeduntil a pick-up circuitfor'this device EPV is closed. In thearrang'ement shown,-

lio

the device EPV is again. automatically picked A up as soon as-the speedhas been reduced to say-less than 2 miles'per hour, as manifested by theclosure of contacts 69 governed by thespeed sector 20. "This pick-upcircuit for the device EPV is readily traced in the draw ing.

' It should be noted that the push button PB has been protected againstmisuse ;which might be effected by tying it down. or .other- 5 wisefastening it so as to place 'it'in its Iacknowledging positionpermanently, by ,pro-x v1d1ng this push button with a normally closedContact opened when'thepushbutton is depressed and included in theenergizing circuit of the brake control device EPV. The

device EPV does however not depend for-its energlzation on thispushbutton contactexcept at times whenthe acknowledging shaft has almostreached its ultimate position. That is, after a given distance ofmovement of the: train the acknowledging shaft-has r0, tated to aposition to cause the contacts 63-, to open and under this condition thestick ci-r'- cuit for the EPV depends for its energy on I the integrityof the branch circuit in multiple with these contacts=-63-, namely thenormally closed contact 4A of the push button PB. In other words theengineer is required to have: the push button. in normal position toavoid a brake application a short, distance before the acknowledgingshaft reaches its ultimate position, so that he is prevented from tyingor otherwise fastening this push button in its active positionpermanently.

The operation of the acknowledging cam shaft has thus far not changedthe position of the toggle switch mechanism asso ciated'with therestoring cam. 30, because the" toggle spring89 maintainsthis mechanismin the position in which it is placed by" the cam 30, and since this camhas not yet been turned far enough to allowthe cam portion" 70 to engagethe roller88, this toggle switch mechanism still remains in; its normalposition.

tion, and as soonas these members are moved After the train: hasproceeded along the track with the cam starter magnet HCS deenergizedsubstantiallythe distance atwhich a repeated acknowledgment is required,the cam portion of the restoring cam 30 en'- gages the roller 38 andthereby moves the members 32 and 33 from their normal posibeyond the midstroke, the compressed spring 39 completes the movement of the togglemechanism to the dotted position, so'that the contacts 71 and 72 bridgetheirrespecti-ve sta tiona ry contacts. With this toggle switchmechanism in its dotted position, another auxiliary circuit for thebrake control device EPV is closed,which circuit may be traced asfollows :beginning at the battery B, wire 73, contact 71 of. the toggleswitch mechanism, wires 74 and 54, cam-governor contacts 23, wire 55,stick contact 56 of the 'EPV, wires 57 and 58, windingof the EPV, wire59 to the common'return wire C. I I v From the tracing: of this'circuit,it readily appears that no acknowledgment is required so long as. thetoggle switch mechanism assumes its abnormal-dotted position; Also, withthis toggleswitch mechanism in its ab-- normal dotted. position, anauxiliary circuit for energizing the acknowledging cam-starter magnetACS is completed, which maybe traced as follows :-beginning attheterni-in al of the battery B, wire76,icontact-72ofthe tog Igle switchmechanism, wires 7 7 and 4:8, winding'of the cam starter magnet AGS,wire49 to, the common return wire C. With-this cam starter magnet ACSenergized the: acknowledging oam shaft 25, by reason of its biasto i nrma p si ion, is retu ned. tethe' no mal speed cam shaft.

position, in which it is illustrated, and it should be noted that uponits return to normal the momentary opening of acknowledge ment enforcingcontacts 51 will: not effect a brake application, even though noacknowledgment is made just prior to this return of the cam, because thedevice EPV is energize'd through the contact 71 of the toggle switchmechanism during the returning cycle of the acknowledging cam shaft 25..

With the toggle switch mechanism returned to normal, the energizingcircuit for the cam starter magnet ACS is again broken and the cycle ofoperation of the acknowledging shaft 25 is repeated, this continuing solong as trafic conditions are dangerous and contact 46 is open. Whentrafiic conditions clear upIthe cam shaft 16 for well known 6 reasons isrestored, contacts 46 are closed and the cam shaft 25 is restored tonormal.

We have just considered how the acknowl edgment enforcing contacts 51are. shunted by contacts 71 of the toggle switch mechanism uponrestoration of the acknowledging shaft by this toggle switch mechanism.Let us now considerconditions when this acknowledging shaft is restoredby reason of a change to clear trafiic conditions, that is, let

us assume that traflic conditions clear up and I that the. acknowledgingshaft is restored by reason of the restoration of the permissive Underthese conditions noacknowledgment is required inspite of the opening ofcontacts 51 because the device EPV is now energized by the followingcircuit closed when the main relay MR is in its energized condition;from terminal B, contact 26' of relay MR, wire 27, cam-governor contacts23, wire 55, stick contact 56 of EPV,

wires 57 and 58, winding of EPV, wire 59 to the common return wire 6.

The apparatus described therefore, in addition to requiring the engineerto restrict the speed of the train in accordance with the signalrestrictions ahead to avoid an automatic brakeapplicati'on and theresulting penalty requiring the train to be broughtsubstantially to astop, requires the engineer V to acknowledge the first danger signal (thtrain. speed having" been" automatically re quired to be restricted to aminimum of, for

example, 15 miles per hour on passing a can- 'tion signal, due toinitiation of HCS) and perform a similar acknowledging act at repeatedintervals of distances so long as the.

train is traveling in danger or cautionterritory. The penalty forfailure of the engineer to manifest hisvigilance, by performing themanual act called acknowledgment,

also consists in requiring the train to be brought substantially to'astop. The mechanism provided to carry out this ma-ni-festw' tion of hisvigilance not only protects the train in case the engineer is dead orincapacitatfidibut also p tect t e t ni theeveet 7 simple typeofautomatic train control system to which the present invention has beenapplied, and having illustratedarat-her specific .mechanism forcarrying'o ut the functions otasystem embodying the present invention,it is desired to be understood that this has been done for therpurposeof illus trating the invention rather than showing the scope of theinvention or the particular mechanism preferably employed in practice,since, for nstance, the same general arrangement wofrrequiringacknowledgment by the" distance interval maybe applied to eitherintermittent orthree-position continuous inductive type train controlsystems by making suitable additions and changes toadapt theinventiontosuch systems, and all without departing. from the scope oftheinvention or the idea otmeans underlying the'samefl What isclaimedasnewand desired to'bei secured by Letters Patent is 2'- i e1.:In an automatic train control system, the combination ofa speedrestricting device governed in accordance with traffic conditions aheadand initiated if traflic conditions ahead aredangerous so as togradually re-' duce thepermissivespeed at which the ve-Z ing the brakesregardless of any substantial speed at Which thetrain is traveling andeffective a predetermined distance after said speed restricting, devicehas been initiated, a'ndjmeans for preventing said last mentioned meansfrom applying the brakes effective if actuated at repeateddistanceiintervals. 2. In an automatic train control system thecombination of a brake setting appliance, means requiring t'he'engineerto manifest his vigilance upon the approach ofhis train to a signalsetat;danger andtherea'ft'er at repeat- "ed distance intervals by actuatinga manumanually operable device when required, and 'it the engineermaintains said (IGVICQ operated for more'than a predetermined distanceinterval. i V v V 3.' An automatic tra'n control system comprising,a'brake setting appliance, means for rendering said applianceactiveincluding a r permissive speed device and an actual speed device andeffective if the actual speed ex ceedsthe permissive speed, and othermeans for rendering said appliance active includ ing means effectiveafter the train has traveled a predetermined distancein dangerousterritory unless a suitable manually operable device operableindependently of the train" Sped, is p r ted at repeated distance{intervals of travel. I i a 4. An automatic train fects'an automaticbrake application; twoindependent means for maintainingsaid deviceenergized, one of which is efie'ctive so long as tlle tl'illn istravelng in clear territory and a control system (50m prising, a normallyenergized stick electro-' responsivedevice which is de-energized' ef-7'5 predetermined distance in danger territory,"

and the other of which-is effective if a suitable manually operabledevice is operated repeated distance intervals. 7

; 5. In an automatic train control system, ve-

hicle-carried apparatus comprising a permissive speed means whichappliesthe brakes of the train it thespeed is excessive, means forinitiating said permissive speed means under dangeroustrafficicdnditions ahead for rendering it-activeafter a given intervalof V e-V hicle travel from the point in tiated to impose a minimum speedrestriction, distance gov:

ernedmeans forsuccessively actuating a cab signal and a device forimposing an a m maticbrake' application regardless of speed above; apredetermined minimum after a given distance of vehicle travel from thepoint a at which said mi'nimumspeed restriction was imposed, andmeansincluding a' manually.

hicle may travelwithou t incurring an autooperable member forpreventingthe"auto matic brake application, means for a-pply-' maticbrake application regardless of speed provided said manually operablemember is operated at predetermined successive intervals of'vehicletravel from the point at Which said minimum speed restriction wasinitiated] 6. In an automatic train control systcm,'the combination of ashaft normallyassuming its biased inactive stationary position,"normallyinactive means governed in 'accor'dancewitlr traflic conditions aheadwhich when active rotates said shaft from its biased position, and meansgoverned by said shaft and effective first mentioned means is initsactivecondition. V i

7 In an automatic train control system, the

combination of a normally energized brake control device whichde-energized effects an automatic brake application, speed governedmeansfor de-energizing said brake control device if the speed of the.train is "excessive, means for de-energizing said brake. control deviceregardless of the speed of the I train,-provided it beabove'apredetermined.

minimum, effective under predetermined traffic conditions alwadamanuallyoperable gnome-4.:

and danger traffic conditions, a normally energized brake control deviceenergized by a stick circuit, speed controlled mechanism governed-bysaid control relay for controlling said brake control device, meansgoverned by said control relay formomentarily breaking the stick circuitof said brake control device at repeated intervals of distance andeffective so long as said control relay is deenergized and regardless ofthe speed of the train, and normally inactive manually operableacknowledging means for shunting the break in said stick circuiteffected by said last mantioned means. I

9. In an automatic train control system of the two position continuousinductive type, a car-carried control relay energized in response tocurrent flowing in the usual track circuit ahead of the train underclear traffic conditions and de-energized under caution and dangertraffic conditions, a normally energized brake control device energizedby a stick circuit, speed controlled mechanism governed'by said controlrelay for controlling said brake control device, means governed by saidcontrol relay'for momentarily breaking the stick circuit of said brakecontroldevice at repeated intervals of distance and effective so long assaid control relayiis deenergized and regardless of the speed of thetrain, normally inactive manually operable acknowledging means forenergizing said brake control device in spite of the break in the stickcircuit effected by said last mentioned means, and means forde-energizing said brake control device if'said manually operableacknowledging means is not re turned to its normal position after eachoperation thereof.

, 10. In an automatictrain control system of the type in whichinfluences corresponding to traffic conditions are continuouslytransmitted from the trackway to a moving vehicle, a brake settingappliance maintained inactive in response to said influences while thevehicle is traveling under favorable traffic conditions ahead, meansrequiring the engineer to manifest his vigilance when influencescorresponding to unfavorable traffic conditions are first transmittedfrom the trackway and thereafter atrepeated distance intervals so longas unfavorable trafiic condi tions exist by'actuating' a manuallyoperable device, and means for actuating said brake setting; applianceif the engineerfails to,

actuate saidf manually operable device when required. 7

11. In an automatic train controlsystem, the'combination of a brakesetting appliance, means driven in accordance'with'the progress of thevehicle for actuating said brake setting appliance at repeated distanceintervals:

under unfavorable trafiic conditions, and a manually operabledeviceroperable independ' ently of the train speed; acting. to preventthe actuation ofsaid brake setting appliance by said means ifoperated'at repeated distance. intervals. 1 i

12. In an automatic train control system,

the combination'of' a brake'setting appliance,

means driven in accordance with the-progress of the vehicle foractuating said brake see ting appliance atv repeated distance intervalsunder unfavorable traffic conditions, and a manually operable deviceactingto prevent the actuation of said brake setting appliance bysaid'means it operated at repeated distance intervals, said manuallyoperable device including means for actuating saidbrake settingappliance if said device is maintained operated for more than apredetermined dist tance interval.

1'3. 1 In an automatic train control system, the'comb'ination ofanormally energized" brake control device which ifde-energized' efiectsan automatic brake application, speed governed means for de-energizingsaidbra'ke control device if" the speed of thetrain is excessive, rotarymeans driven in accordance with the progress oft-he vehicle forde-eneixgizing said brake control device regardless of the speed of thetrain above apredeterminedf slow speed limit and effective underpredetermined traffic conditions ahead,a manually operable:acknowledging device whichif operated from'its normal position preventsd eenergization of said brake control device ir= respective of thecondition of said rotary" means, and means controlled. by said firstmentioned means for de energ'iz-in'g fsaid? brake control device If saidacknowledging means is not returned to it's normal position.

14. In an automatic train control system,

vehicle carried apparatus comprising a permissive speed means whichapplies the brakes of the trainif the speed is excessive, means forinitiating said permissive speed means under dangerous traflicconditions ahead for rendering it active after a given interval ofvehicle travel from the point initiated to impose a minimum speedrestriction, distance governed means for successively actuating a cabsignal and a device for imposing an automatic brake application eventhough the speed of the vehicle is below said minimum speed after agiven. distanceof vehicle travel IOQ from the point at which saidminimum speed restriction Was imposed, said distance gov-- erned meanscomprisingfashaft normally biased to an inactive position, normallyinactive means initiatedby said permissive speed means When'said minimumspeed restriction is imposed, and when: in tiated rotating said shaftfromits lIlEtCtlVQ'POSltlOIl in accordance with the progress of thevehicle, means governed by said shaft and effective if said shaft isrotated through a certain angle for permitting said shaft to return toits biased position and for again permitting the'first mentioned meansto rotate said shaft against its bias,"wher eby the cycleof operation ofsaid shaft is repeated so long as said first mentioned means is in itsactive condition, and means including a manually operable member for V{preventingthe automatic brake application regardless of speed 'above' apredetermined lovv limit providing said manually operable member isoperated at predetermined successive intervals'of vehicle travel fromthe point atwhich said minimum speedrestriction Was initiated; 1

.15. In an automatic the twojposition continuous inductive type,

imined distance interval; y 'In testimony whereof I aflix my signature.

acar-carried control relay energizedvin're- {sponse to current flowingin the usual track circuit ahead of the train under clear traflicconditions and de-energized under caution and danger traflic conditions,a normally energized brake control device energized by a stickcircuit:andadapted to apply the vehicle --brakes when *de-energized,speed control I mechanis'm governed by said control relay forcontrollingthe energization of said stick circuit, distance operatedmeans governedby said control relay for momentarily breaking said stick circuit atrepeated distance intervals and effective so long as said control relayis tie-energized and regardless of the speed of the train, anormallyinactive manually operabledevice acting when operated to ishunt thebreak in said stick circuit effected bysaid distance operated means, andmeans for breaking said stick circuit if saidmanuallyvoperableacknowledging device is main-' predetertained operated for morethan a WVINTHROP Ki HONE.

train control system of

